Various constructions of athletic shoes are known, particularly such types of athletic shoes as are intended for use by joggers and those engaged in sporting activities involving a considerable amount of running. Such constructions of shoes as exist do not optimally embody in any one shoe construction all of the desirable features as should be contained therein so as to effectively protect the wearer's foot from discomfort, undue strain, injury, and the like. For one thing, such types of shoes invariably do not properly support the foot of the runner as the foot makes contact with the ground during the course of a running stride. In the normal situation, the lateral rear part of the runner's foot at the heel makes contact with the ground first since in a running stride, the legs contact the ground closer and closer to its line of progress thus the feet tend to tilt outwardly. Following such initial contact at the lateral rear corner, the foot should then have a contact course which moves forwardly on the sole and inwardly towards the mid-part of the foot until it approaches the region of the phalangal-metatarsal joints of the foot at which point the line of contact desirably should move toward the medial side and under the phalangal-metatarsal joint of the first metatarsal bone to position and support the foot for push-off at that joint. Since the human foot as indicated tends to turn or tilt outwardly in the course of running, prior art shoes which generally have a flat sole render the runner's foot susceptible to counter-tilting upon making ground contact with such counter-tilt being toward the medial side and frequently of such magnitude that proper lift-off at the first phalangal-metatarsal joint is not possible thereby causing considerable improper strain on the foot with possible consequent injury. Moreover, such forms of athletic shoes as are known for use by runners, do not embody therein sole structure which allows for independent flexure of the sole along the critical metatarsal-phalangal joint. In other words, the human foot, during lift-off in the course of a running stride, bends in one direction along a line of action between the medial side and the second metatarsal-phalangal joint and along a different course of action between the second and fifth phalangal-metatarsal joints. As a result, the lift-off extension of the toes does not follow the position that is desirable since prior art shoes generally bend along a line of action which is generally directed straight transversely of the longitudinal axis of the foot, i.e., extending directly between the first and fifth phalangal-metatarsal joints.
Additional drawbacks of prior art athletic shoes include the lack of same to properly provide a suitable contact surface at the heel to take into account that the foot makes first ground contact high up on the heel with a following heel rotation that oftentimes is improperly supported.